## Abstract

We investigate how universal the collective behavior, due to the many-body interactions in polydisperse hard-sphere systems, is at higher volume fractions. We perform two types of computer simulations, a Brownian-dynamics simulation on colloidal suspensions of hard spheres, where the hydrodynamic interactions between particles are neglected, and a molecular-dynamic simulation on atomic systems of hard spheres. Thus, we show that the long-time self-diffusion coefficients D_{S}^{L} in both systems become singular as D _{S}^{L}(φ)̃(1-φ/φ_{c})^{2} because of the collective interactions due to the many-body collision processes, where φ is a particle volume fraction and φ_{c}≃0.586 for 6% polydispersity. Although D_{S}^{L} exhibits the same singular behavior as that obtained theoretically for the monodisperse suspension with the hydrodynamic interactions, no liquid-glass transition is found because even the polydisperse hard-sphere systems crystallize without the hydrodynamic interactions for all φ above the melting volume fraction, which is lower than φ_{c}.

Original language | English |
---|---|

Pages (from-to) | 367-379 |

Number of pages | 13 |

Journal | Physica A: Statistical Mechanics and its Applications |

Volume | 328 |

Issue number | 3-4 |

DOIs | |

Publication status | Published - 2003 Oct 15 |

## Keywords

- Collective interactions
- Hard-sphere systems
- Long-time self-diffusion coefficient
- Singular behavior

## ASJC Scopus subject areas

- Statistics and Probability
- Condensed Matter Physics